A retained placenta is when a cow or heifer fails to expel their afterbirth within 24 hours post-parturition.
In some cases, in can take a number of days for a cow to expel their afterbirth, but for most it happens within a number of hours of calving.
Causes of retained placenta in cows
- Subclinical milk fever;
- Overfat cows;
- Selenium/vitamin E deficiency;
- Difficult calving;
- Premature birth/abortions/ still births;
- Low immune system.
Retained placenta in cows leads to an increased risk of metritis, ketosis and mastitis. Ideally, you would try and avoid them from happening – but this is not always possible.
Often treatment is not required, as a cow will expel the membrane, but cows or heifers that continue to hold their cleaning after four days need to be seen by a vet.
If the cow or heifer goes off her feed, has a high temperature or has a reduced milk yield, then veterinary assistance should be sought straight away.
Manual removal is not advised, but your vet may recommend trimming of the membrane to avoid bacteria entering the uterus.
Manual removal can lead to an infection within the cow’s uterus and can delay the onset of heat by up to 20 days.
A retained placenta can lead to an infection within the uterus, which can have an impact on a cow’s fertility in the future.
Cows that have a retained placenta should be checked prior to breeding to ensure that there is no lingering infection.
Not detecting this infection prior to the start of breeding can lead to the cows calving interval being extended, or them not going in-calf.
A pre-breeding scan should be organised and any cow that had issues around calving or has not been seen cycling should be checked.
Failing to detect these cows could result in them being culled from the herd.